One of the more difficult challenges facing building enclosure designers and specification writers is detailing critical interfaces between various building enclosure assemblies and systems. These junctures are arguably more vulnerable to water leakage, air leakage and condensation due to thermal bridging than any other. Several ASTM standards have been developed to address various performance issues separately, but the successful integration of flashings, air barrier, thermal barrier and vapor retarder is very project and product-specific, requiring a keen understanding of various performance criteria.

This presentation introduces design objectives for the roof/wall, window/wall and other interfaces, and discusses detailing concepts for various applications. We review design principles that lead to effective details to mitigate air flow through the enclosure, and provide examples of how air barrier continuity can be achieved. Technical and practical limitations of various building materials used are discussed, and the potential consequences of inadequate detailing and construction are illustrated through case studies.

Learning Objectives:

Review the mechanisms of air and moisture migration through building enclosures, and examine interfaces between enclosure systems and assemblies that are critical to air leakage and moisture control.

Understand the difference between vapor retarders and air barriers, and how the performance of the enclosure is affected by the HVAC system.

Examine the fundamental errors that cause failures, and how to prevent them.

Vince Cammalleri, AIA is a Senior Principal in the NYC office of Simpson Gumpertz & Heger Inc. He has extensive experience in the design, investigation and repair of walls, roofs, glass curtain walls and windows. He leads the Building Science Practice group at SGH, specializing in the analysis of moisture migration and condensation issues in the building envelope caused by heat, air and vapor flow. Vince has lectured as an adjunct professor at the School of Architecture, McGill University and as a visiting lecturer at the Department of Architecture and Urban Planning, Massachusetts Institute of Technology. He has published numerous papers related to building technology in the United States and Canada, and is an active member of ASTM International.